Floyd Mayweather Jr. ends Victor Ortiz with a single and bizzare punch in Round 4!

Floyd Mayweather's knockout punches on Victor Ortiz, though technically legal, were anything but ethical.
Mayweather ran his career record to 42-0 and stole away the WBC Welterweight Championship belt from Ortiz with a devastating two-punch combination in the fourth round.

To characterize the bout-ending sequence of events as strange, would be an understatement. "Surreal" might work, but "dirty" just sounds better. "Cheap" and "gutless" would work as well, possibly even better, depending on how strongly you feel about the result.
The fiasco began in the fourth round when Ortiz recaptured the momentum with a quick series of blows, pummeling Mayweather against the ropes. Amidst that barrage, Ortiz inexplicable launched his head at Mayweather's, thereby forcing referee Joe Cortez to intervene and register a point deduction on Ortiz's part for an illegal headbutt. Ortiz immediately apologized to Mayweather for what might have been interpreted as a cheap shot on his part.